1. Field of the Invention
The present invention relates to an interconnect of the group III-V semiconductor device and a fabrication method for making the same, and particularly to a copper interconnect of the group III-V semiconductor device and a fabrication method for making the same.
2. Description of the Prior Art
The conventional group III-V semiconductor devices, for example, gallium arsenide (GaAs) devices, which include hetero-junction bipolar transistor (HBT), high electron mobility transistor (HEMT) and metal-semiconductor field-effect transistor (MESFET), all use gold as the material of the metal line. However, as the line width of the metal line reduces gradually, the current density carried by the metal line increases accordingly. For the conventional metal line mainly made of gold, the resistance of the gold metal line may become higher and higher. Moreover, because the thermal conductive coefficient of gold is small, the thermal conductive property of the high speed semiconductor device is affected. If the heat cannot be transferred to outside easily, the electrical property and reliability of the device will be adversely affected as the temperature of the device rises.